src: drop 'virtual' from functions marked 'final' or 'override'

Change-Id: Ieb6df864ab82f77b2bee9e83aa0bfa2005715950
Refs: #3857
diff --git a/src/security/command-interest-validator.hpp b/src/security/command-interest-validator.hpp
index e789f09..c377142 100644
--- a/src/security/command-interest-validator.hpp
+++ b/src/security/command-interest-validator.hpp
@@ -88,7 +88,6 @@
      *  and causes every command Interest to be processed as initial.
      */
     time::nanoseconds timestampTtl = time::hours(1);
-
   };
 
   /** \brief error codes
@@ -129,7 +128,7 @@
    *
    *  The validation request is rejected if any step in this procedure fails.
    */
-  virtual void
+  void
   checkPolicy(const Interest& interest, int nSteps,
               const OnInterestValidated& accept,
               const OnInterestValidationFailed& reject,
@@ -139,7 +138,7 @@
    *
    *  The validation request is redirected to the inner validator.
    */
-  virtual void
+  void
   checkPolicy(const Data& data, int nSteps,
               const OnDataValidated& accept,
               const OnDataValidationFailed& reject,